After hearing about two hours of presentations and public comments on the Bitcoin mining operations in Bonner, the Missoula County Commission on Thursday postponed making a decision on a proposed one-year ban on new or expanded cryptocurrency activity until August.

The public comments were split fairly evenly in support and in opposition to the potential interim emergency zoning regulations the county is considering. Some 75 people crowded into a conference room in Missoula’s courthouse annex to offer opinions on the proposal.

But at the end of the hearing, Commissioner Jean Curtiss noted that she feels that “we all understand that we don’t understand.”

“We don’t know all the impacts in the future or the long game,” Curtiss said.

Commissioner Cola Rowley added that it might be good to have more time for “education and outreach” before moving forward on the one-year moratorium.

“This has been fascinating and I heard a lot of new information,” Rowley said.

Bitcoins are the most popular of about 1,200 types of cryptocurrency, which is an intangible digital asset with a value that varies from day to day, or even minute by minute. The cryptocurrency is “mined” by high-powered computers solving complicated mathematical problems, and when successful the currency is put on a public transaction ledger called a blockchain.

The system is set up so that a cryptographic puzzle is solved and new transactions are added to the blockchain about every 10 minutes, according to Diana Maneta, the Missoula County energy conservation and sustainability coordinator. As more miners join the system, the puzzles become increasingly difficult and require more computing power — and more electricity — to solve.

Montana and the Pacific Northwest are becoming popular for large cryptocurrency mining because the climate helps cool the hundreds of computers needed for large operations to move, and the cost of electricity is fairly low. But the large operation at the old mill site in Bonner also uses more than 400 fans, and their blades create a low humming noise that bothers many of the residents.

“The noise is bad,” said Joanne Weimer. “Some people are going to have to move. Our property values are going down. The references that this is the same as the mill is totally wrong. This is not the same kind of noise.”

Along with the noise, the commissioners are concerned about the increased greenhouse gas emissions from the large and increasing consumption of cryptocurrency mining operations. They also are worried that the rapid growth in electricity demand may pose a reliability and safety risk to local electric distribution systems, and affect electric rates for other customers. In addition, they’re concerned that the high energy loads could pose a fire hazard, and create electronic waste because the computers are running all day, every day.

Four electric utilities have imposed moratoriums or restrictions on cryptocurrency mining, including the Flathead Electric Cooperative, as have five cities in Washington and New York, and several Canadian municipalities.

Missoula’s Julie Merritt told the commission that this is the type of situation that clearly speaks to the need to go slowly and carefully.

“It makes me think of logging — it was great, provided good jobs for a long time, then when the easy-to-get lumber was harvested, people like Champion moved on and took the jobs,” Merritt said. “I hope we can learn lessons from past examples and take time to study this and make sure we’re not setting ourselves up for the same problems.”

But the Project Spokane supporters note that they’re in the process of switching out the fan blades to deal with the noise issue, and they added that the Bitcoin operation is adding jobs to the area. Dan Bordner, who owns a small electrical company, said he’s been able to hire more people because of the operations. Desireh Kissinger said she was hired full-time at Alter Enterprise, a computer support company, and they’re now able to train more Montana Tech computer interns.

In an eight-page letter to the commission, Project Spokane Manager Dan Stivers also responded to each of the commission’s five concerns. He noted that they buy their power from Energy Keepers Inc. at the former Kerr Dam, which is a clean, renewable hydroelectric source that generates more power than it can sell, so greenhouse gas emissions and impacts on other electric consumers aren’t an issue.

They’re in compliance with all existing laws, regulations and codes that should mitigate concerns about fire risk at their facility, and their used or spent hardware is either recycled, repurposed or re-marketed, he said.

“You need to consider the long game, not only for Bonner but for Missoula County and the State of Montana,” Stivers said. “This is emerging technology … we are like a…